Noise Analysis of Pumps by Sunpace

Many experienced car mechanics know what went wrong when listening to the car. In fact, the pump is the same, you can judge the condition of the pump by listening to the sound.


The pump is mainly divided into three pieces of noise, the first is the pump body noise, the second is the motor noise, and the third is the pipeline noise. First of all, you can hear the three kinds of noises and you can tell which part is wrong. Then judge the specific situation according to the noise level and whether there is noise or the like.

The noise of the pump is mainly divided into three parts in terms of its sounding part: pump noise, motor noise, and pipeline noise.When the impeller is driven by the pump shaft for high-speed rotation, a force acts between the blade and the water flow driven by the blade to transfer the applied mechanical energy to the flow of the thrown water.

When the impeller rotates, the circumferential velocity of the water flow point on the blade increases in the radial direction. Under the increasing centrifugal force, it flows substantially radially through the impeller and is swung toward the impeller outlet, thereby making the water flow. Get kinetic energy.

Since the number of blades on the pump impeller is limited, and the pressure distribution in the circumferential direction at the impeller exit is uneven, when the water periodically passes through the tongue portion of the inlet volute chamber of the vane, the change in pressure is transmitted. On the pressurizing side, this pressure pulsation produces noise from the pump body and vibration of the pump casing water outlet.

At the same time, in the interior of the impeller, vane and pump casing, the occurrence of vortices is unavoidable, especially in the state away from the design point of the pump, the vortex irregularly occurs and disappears, and noise and vibration are also generated.

The pump noise spectrum has an intermediate frequency characteristic, and the high frequency sound is small. There is usually a peak in the low frequency range of 31.5-125 Hz, and the sound level is generally 85-101 dB. As the speed and the head increase, the noise level also increases.